多个文本字段输入视图的多个选择器视图很快

当我单击第一个textField时,pickerView1成功显示,文本字段显示数据,但是当我单击第二,第三和第四个文本字段时,会出现第一个pickerView.
我怀疑错误在于inputView声明.

如果你能帮助为pickerView添加一个“完成”按钮,我将非常感激.

我的代码：

class ViewController1: UIViewController,UIPickerViewDelegate
{

    @IBOutlet var pickerView1: UIPickerView!
    @IBOutlet var pickerView2: UIPickerView!
    @IBOutlet var pickerView3: UIPickerView!
    @IBOutlet var pickerView4: UIPickerView!

    @IBOutlet var textField1: UITextField!
    @IBOutlet var textField2: UITextField!
    @IBOutlet var textField3: UITextField!
    @IBOutlet var textField4: UITextField!

    var hazards = ["a","b","c"]
    var reasons = ["d","e","f"]
    var site = ["v","h","i","j"]
    var line = ["k","l","m","n"]

    override func viewDidLoad() {

        super.viewDidLoad()
        pickerView1 = UIPickerView()
        pickerView2 = UIPickerView()
        pickerView3 = UIPickerView()
        pickerView4 = UIPickerView()
        pickerView1.delegate = self
        pickerView2.delegate = self
        pickerView3.delegate = self
        pickerView4.delegate = self

        self.textField1.inputView = self.pickerView1;
        self.textField2.inputView = self.pickerView2;
        self.textField3.inputView = self.pickerView3;
        self.textField4.inputView = self.pickerView4;
    }

    func numberOfComponentsInPickerView(pickerView: UIPickerView) -> Int  {
        return 1
    }

    func pickerView(pickerView: UIPickerView,numberOfRowsInComponent component: Int) -> Int {

        if pickerView.tag == 0 {
            return hazards.count
        } else if pickerView.tag == 1 {
            return reasons.count
        } else if pickerView.tag == 2 {
            return  site.count
        } else if  pickerView.tag == 3 {
            return line.count
        }
        return 1
    }

    func pickerView(pickerView: UIPickerView,titleForRow row: Int,forComponent component: Int) -> String! {

        if pickerView.tag == 0 {
            return hazards[row]
        } else if pickerView.tag == 1 {
            return reasons[row]
        } else if pickerView.tag == 2 {
            return site[row]
        } else if pickerView.tag == 3 {
            return line[row]
        }

        return ""
    }

    func pickerView(pickerView: UIPickerView,didSelectRow row: Int,inComponent component: Int)  {

        if pickerView.tag == 0 {
            textField1.text = hazards[row]
        } else if pickerView.tag == 1 {
            textField2.text = reasons[row]
        } else if pickerView.tag == 2 {
            textField3.text = site[row]
        } else if pickerView.tag == 3 {
            textField4.text = line[row]
        }
    }
}